Burglar alarm



May 12, 192s. 1,537,895

J. D. SMITH BURGLAR ALARM Filed sept. 1, 1921 einem do Patented May 12, 1925.

UNITED STATES PATENT OFFICE.

J'O'Hy D. SMITH, OF MAR-YSVILLE, CALIFORNIA.

BURGLAR ALARM.

Application filed September To all whoml t may concern:

Be it knowny that I, Jol-IN D. SMITH, a citizen of` the United States, residing at Marysville, in the county ot Yuba and State oft California, have invented certain new and usetul- Improvements in Burglar Alarms; and I do declare the following to be a full, clear, and exact description ot the invention, such as will enable others skilled in vthe artto which it appertains to make and use the same.

This invention relates to an improved burglar alarm, and it has for its principal object to provide a device ot this class embodying ,two independent successively operable circuits, one of which is controlled by the like and continue to do so until this circuit is broken by manually controlled means, as hereinafter described and claimed.

Another object of the invention is to pro- 'vide a burglar alla-rm embodying the aforesaid two circuits, the primary or closure controlledl circuit serving to actuate a trip which normally supports the movable element of a switch in a raised inoperative position, this switch when closed serving to close the seconda-ry or signal circuit.

Another object of the invention is to provide a burglar alarm; embodying the circuits mentioned, the aforesaid switch constituting a part of both of said circuits and thereby providing a novel arrangement of parts whereinwhen the secondary circuit is closed, the primary lcircuit is absolutely broken, this result not being obtained until the switch is rendered effectlve.

Astill further object of the invention is to provide an arrangement wherein the trip and switch referred to are enclosed in a housingwhich is concealed to prevent the intruder from obtaining access thereto and rendering the switch which controls the secondary circuit inoperative.

Other objects and advantages of the invention will be apparent during the course of the following description. f

In the accompanying drawings forming a part ot this specification and in which like numerals are employed to designate like parts throughout the same:

Figure 1 is ya sectional view through the mechanism casing showing the mechanism 1, 1921. serial No. 497,525.

in elevation and the parts in their normal inoperative position.

Figure 2 is a sectional view including thc electric circuit and showing the parts in positions they take when the secondary or signal operating circuit is closed.

Figure 3 is a sectional view taken substantially on the plane ot the line 3-3 of Fig. 1.

In carrying out the invention, I make use of an asbestos lined housing or container l which I arrange in a place where it will be practically concealed from persons entering the house. By preference however, it will b'eyarranged in some convenient position to enable the occupants of the house to obtain easy access thereto for resetting the signal closing switch, that is, for rendering this switch effective. Among other parts which are arranged in the container is an upstanding bracket 2 embodying spaced uprights 3, one ot which serves to support a pair of electro-magnets 4f.' The exact manner of connecting these magnets with this upright is not 'shown as this may be accomplished in any suitable way. It is 4of course understood that the magnets will beinsulated from the upright on which it is arranged by means of a strip of material 5. As a matter of fact, insulating material will be employed at all necessary points to prevent possible short-circuiting and it will hardly be necessary to point-out just where such material is located. As before indicated, a vertically disposed armature 6 is co-operative with and attracted by the magnets and this armature is connected with a suitable spring 7 which serves to disengage it from the magnets and cause it to resume its original position after the magnets are deenergized. It is to. be pointed outhere the armature 6 constitutes what may be conveniently termed a trip, and has its upper tree cndvdirected laterally as indicated at 8 so that it will effectively serve in this capacity. It may be stated here that this trip serves to support and retain a substantially Ushapedmember 9 in the raised position indicated in Fig. l, this member being pivoted at its ends to the upper ends of the uprights of the aforesaid bracket and having its intermediate or connecting' portion rested on the laterally directed end of the trip. One of the arms ot the part 9 carries a blade 12 which is designed for co action with the contact clip 13 supported on one ot the uprights of the brackets. It is obvious that these parts 12 and 13 form an ordinary knife switch which, as before indicated, constitutes apart of a signal operating circuit to be hereinafter described. Part 9 is, when the trip is disengaged therefrom, lowered by gravity to engage the blade with the clip so as to close the switch and it remains in this position until it is raised by manually controlled means. In the drawing, this means comprises a flexible cord 1l which is connected with the part 11 and is passed oi'er pulleys 15 arranged inside of the aforesaid housing 1. It is understood that the free end of this cord which is arranged on the outside of the housing is extended down toward the floor so that it will be at a convenient place where it can be gr'ipped by a person standing on the floor for the purpose of elevating the member 9 and again engaging it with the trip. To permit the arm to readily drop to its operative position and to prevent the weight of the cord itself from interfering with the dropping, a coiled spring 16 is connected with the cord and serves to lift the cord after it is released. I may mention here that suitable brackets or the like 1T are arranged inside of the housing for thel purpose of supporting' the aforesaid pulleys 15. It is also to be pointed ont that in addition to the aforesaid parts,.there is also arranged in the housing a laterally disposed contact member 18 which is connected with the extreme upper endA of one of the uprights of the bracket Q and' has its outer extremities directed laterally as indicated at 19 and bevelled so that when the part 9 is raised, by pulling the cord'14 downwardly. this bevelled end will engage the same for a purpose to be hereinafter set forth.

As before intimated, two independent circuits are employed with my arrangement and one of these circuits, which includes the wires 20, 21, 22 and 23, may be termed the primary circuit. This circuit is controlled, as before pointed out, by a closure, either a door D or window sashes S which are equipped, as already pointed out, with a special circuit closing element or switch which will be described in detail as the description goes on. By carefully tracing the wires just mentioned, it will be seen' that the one indicated by the numeral 20 leads from this special circuit closing device to the uprights 3 on the aforesaid bracket, electrifying this upright, which, as is obvious, is com posed of suitable conducting material. Since the closure and the electro-magnets l are connected with this upright through the me dium of a wire 2l and are connected with each other by a wire 25, they are energized when this primary circuit is closed. A wire 2G leads from the upper magnet to a pin 27 which serves to connect the aforesaid member 18 with the bracket. Hence, when through this pin and then through the member .18 and inasmuch as this member is engaged with the aforesaid arm 9 the current will pass through this arm 9, and through the wire 21 which is connected therewith and leads through the day switch 2S and wire 22 to the battery 29 and finally through the wire 23 to the starting point.

Hence, the passage of the current through the primary circuit is understood. The sec.- ondary or signal operating circuit also includes the aforesaid wires battery 21 and together with the additional wires 3() and 31 which are connected with and operate the bell As previously pointed out, the switch which is made up of the aforesaid blade 12 and clip 13 constitutes a part of this last-named circuit and it is obvious that so'long as the part 9 is supported in the position indicated in F ig. 1, this circuit is broken. However, as soon as the primary circuit has been completed and acts on the trip (i in such a way as to permit the part t) to be lowered, the knife switch just referred to is closed and this secondary circuit is com pleted so that the bell 32 is sounded and is continuously sounded until the switch elements 12 and 13 are disengaged. The manner in which wiring from the window sashes S may be connected with the wires in the circuits already described is plainly shown in Fig. 2 and inasmuch as the' exact arrangement of the wires is immaterial so far as this invention is concerned, such arrangement of wires will not be discussed.

The operation of the improved alarm is doubtless clear after reading the foregoing description. Yet, it may be advisable to insert at this point a brief review of such operation. To this end, it will be seen that during the day time, the key-controlled switch 28 which, as indicated, may be constructed' in any suitable way, is arrangedi so that opening and closin of the door or window will not affect tie electric circuits. However, at night, the switch 28 is turned on and in case either the door or the windows are opened and an attempt is'made, by unauthorized persons, to enter the house by this method, it will be seenA that the primary circuit which is controlled4 by suchv closures, will be closed. In so doing, the aforesaid magnets at will be energized and will attract the trip 6, thus moving the latter in such a way as tol disengage its laterally bent end from the part 9. The latter` will then drop by gravity and in this way break the circuit just referred to. On the other hand, the signal operating circuit will now be completed because the blade 12 will be engaged with the clip 13 and this circuit will be renderedr effective and will remain so until the hanging' portionI of the cord 14 is gripped and pulled downwardly to elevate the part 9 the circuit is closed the current will pass and dispose the mecl'ianism in the housing in its original state, that is, as indicated in Fig. 1. Hence, it will be seen that when the door is again closed, or even if the primary circuit is destroyed, the remaining circuit Will still remain effective and will ring the bell until the occupants of the house care to disengage the signalby operating the manually controlled means referred to above.

By carefully considering the description in connection with the drawings, persons familiar with devices of this class will doubtless be able to obtain a clear understanding of the invention. Therefore, a more lengthy and detailed description is deemed unnecessary.

Since probably the best results may be obtained with the construction and arrangement herein shown and described, this is taken as the preferred embodiment of the invention. However, I wish it to be understood that minor changes coming within the scope of the subjoined claims may be resorted to if desired.

I claim:

A circuit maker and breaker for primary and auxiliary circuits comprisingy a support, an electro-magnet carried by said support and insulated therefrom, a latch forming armature yieldably mounted in operative relation to said magnet and moved out of its normal position when the electro-magnet is energized, an arm of conducting material connected with said support and insulated therefrom, the Winding of the electro-magnet having one end thereof connected with said arm and its other end adapted for connection with one side of a. source of energy, a contact carried by said support in insulated relation thereto and adapted for connection with a lead wire of an aXuiliary circuit, and a swinging arm of conducting material pivotally connected with said support in insulated relation thereto and adapted for connection with a lead wire from the other side of the source of energ said swinging arm being held in an open position and in engagement with the first mentioned arm by said armature until the electro-magnet is energized and draws the armature out of its normal position, the swinging arm then having movement into engagement with said contact to close the auxiliary circuit.

In testimony whereof I have hereunto set my hand.

JOHN D. SMITH. 

